Thallus: crustose, granular-warted, warts often coalescing to form a thick, rimose-areolate crust, rarely strongly reduced areoles: isodiametric to very irregular in outline, 0.10-0.30(-0.70) mm in diam., moderately to strongly convex, ecorticate but sometimes with a loose unorganised alga-free layer of various hyphae surface: yellowish gray, beige or green, dull, often sorediate soredia: globular, 20-25(-45) µm in diam., often as consoredia of 45-70 µm in diam, in poorly delimited soralia (same color as nonsorediate parts of thallus) Apothecia: rounded or irregular to flexuose in outline, single or densely crowded, sessile with a constricted base or ±appressed, 0.5-0.9(-1.7) mm in diam. disc: pale pinkish ochre to orange-brown, flat to moderately convex, dull, finely to coarsely white pruinose margin: prominent when young, persistent, crenulate or granular-sorediate, same color as thallus or covered by terpenoid crystals and then whitish gray, without a parathecial ring amphithecium: present, with an algal layer, laterally 55-110(-150) µm, basally (40-)75-150(-240) µm wide, filled with small brownish granules (soluble in K), with irregularly entangled, short-celled, hyaline hyphae with lumina 1-2 µm wide internally and 1-2(-2.5) µm wide in outer cells, ecorticate parathecium: hyaline, 10-30 µm wide epihymenium: greenish ochre to orange-brown, granular (soluble in K), 5-15 µm thick hymenium: hyaline or pale yellow, 40-50(-55) µm tall; paraphyses: simple or weakly branched and anastomosing, hyaline, with lumina 0.7-1(-1.2) µm basally and 1-1.2(-1.5) µm wide apically; subhymenium: hyaline, 25-70 µm thick; hypothecium: hyaline, (40-)55-150(-250) µm thick asci: clavate, 8-spored ascospores: hyaline, simple or rarely 1-septate, narrowly ellipsoid or often slightly bent, (8.5-)10-15.5(18) x (3-)3.4-3.9(-4.5) µm Pycnidia: ±ellipsoid, 95-135 x 200 µm, immersed in the thallus; wall: unpigmented conidia: filiform and curved, 16-21 x 0.5-1 µm Spot tests: thallus K-, C± orange, KC± orange, P- Secondary metabolites: (a) usnic acid and zeorin; (b) usnic acid, ±thiophanic acid, ±arthothelin, ±4,5-dichloronorlichexanthone (tr.), ±4-chloronorlichexanthone (tr.), ±norlichexanthone (tr.), sometimes thiophanic acid, sometimes arthothelin as major xanthone; (c) usnic acid, arthothelin, 1 unidentified xanthone. Substrate and ecology: on bark and cactus wood World distribution: oceanic western North America south of 28° N Sonoran distribution: Baja California Sur, Sinaloa and Sonora between 5-500 m. Notes: Lecanora perconfusa is similar to L. confusa in outward appearance, but usually has a lighter green or more clearly yellow thallus and narrower and more elongate ascospores. Thiophanic acid and its biochemical precursors, which regularly occur in L. confusa, are missing in many, but not all specimens of L. perconfusa.